This invention pertains to miniature electric lamp assemblies utilizing an improved external interlocking device. It pertains particularly to such lamp assemblies in which a lampbase member is automatically and reliably attached to a socket member by the external interlocking device utilizing a biased elastic detent.
Miniature electric lamp assemblies having various configurations have been produced and used in lamp strings for many years. However, a common problem associated with such lamp assemblies which are electrically connected together in a series arrangement is that whenever parts of an individual lamp assembly may become detached such as during handling or use, the entire lamp string fails. Various interlocking configurations and devices have been developed to prevent such electrical disconnects between the members of a lamp assembly. Examples of known miniature lamp assemblies having such interlocks include U.S. Pat. No. 5,001,615 to Stefanelli which discloses a lamp assembly having an external positive interlock structure for the lampbase and socket members which requires an undesirable second separate motion at assembly to effect an interlocking action. U.S. Pat. No. 5,278,741 to Ehrman discloses a similar conventional lamp assembly but which utilizes an internal locking configuration in which a resilient element of a lampbase member is engaged in a wall opening in a socket member. U.S. Pat. No. 5,367,443 to Hara discloses a lamp assembly in which an upper lampbase member is attached into a socket member by an external flexible finger having an opening which during assembly can be hooked over a rigid lug element of the socket member. Also, U.S. Pat. No. 5,428,516 to Harris discloses an interlock for miniature lamp assemblies in which an upper lampbase member is interlocked into a lower socket member by an L-shaped tongue element having an aperture which is hooked over a rigid lug projecting outwardly from the socket member. However, these known miniature electric lamp assemblies all have various deficiencies in their interlocking configurations and actions. Because of these deficiencies in the known miniature decorative lamp assemblies, further improvements for providing safer and more reliable miniature lamp assemblies have been sought.